Google on Saturday said that the U.S. Federal Trade Commission has begun a review of its business practices.

Yesterday, we received formal notification from the U.S. Federal Trade Commission that it has begun a review of our business. We respect the FTC's process and will be working with them (as we have with other agencies) over the coming months to answer questions about Google and our services, the company said on its official blog.

It's still unclear exactly what the FTC's concerns are, but we're clear about where we stand, it further added.

The probe was first reported on Thursday, when The Wall Street Journal cited sources familiar with the matter saying that the FTC was expected to open an antitrust investigation into Google.

Regulators across the U.S. and in Europe are stepping up their scrutiny of Mountain View, Calif.-based Google, which has the largest share of the U.S. Web-search market. The company, much like Microsoft in the 1990s, may be forced to spend years defending itself against a probe into whether Google uses its lead to keep out competitors and harm consumers.

However, Google defended its practices through the blog post.

Search helps you go anywhere and discover anything, on an open Internet. Using Google is a choice-and there are lots of other choices available to you for getting information: other general-interest search engines, specialized search engines, direct navigation to websites, mobile applications, social networks, and more, it said.